Worldship

Worldships were xel'naga ships capable of landing on planets,[1] as well as remaining above planets when the xel'naga didn't want the inhabitants to notice them.[2] At least one worldship was attacked by the protoss who jumped on it as it took off; the protoss fell to their deaths.[1]

Battle on a worldship

Xel'naga ships were protected by reinforced hulls[2] and sharp crystals.[1] This failed to protect the xel'naga fleet against the attack by the zerg.[2]